The 78-79 Bronco brake system for the most part really sucks. The good thing is that there is a relatively simple and cost effective solution to this problem. Parts from the F-350 brake system can be bolted on for a major increases in braking ability. This article will provide all the info you will need to perform the conversion, including part numbers and pictures for reference.

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The first and most important part of this upgrade is the booster and master cylinder. The '78-'79 Ford F-350 tandem booster (dual 9 1/4" diaphragm) is a direct bolt in that requires only a brake line modification. If you own a 78 Bronco will need the booster from a '78 F350 4WD or 2WD. If you own a 79 Bronco then you need the booster from a '79 F350 2WD only! Also, the '79 F350 with cruise control was yet a different booster. You can get the booster/master cylinder combo at most auto part stores. The largest remanufacturing company is A-1 Cardone and it's part #50-3311 for a 78 model, and part #50-9337 for a 79 model (without cruise control). Those are the p/n for the booster/mc combo. The only change needed here is replacing the line nut fitting on the chamber for the front brakes. The Bronco master cylinder uses a 9/16"-18 threaded nut and the F350 master cylinder uses a 3/8"-24 threaded nut. You must also twist your lines around to the other side of the master cylinder because the F-350 has the fittings on the opposite side. Just find a local shop to double flare your brake line with the new fitting and your done. At this point, if you add the F-350 rear wheel cylinders your brakes will show a major improvement and it is not absolutely necessary to add the Thunderbird calipers, but it is easy enough and will give you even more braking ability.

Comparison pictures of the Bronco and F-350 combo's

Original Bronco ________ F-350 Combo

The brake calipers are the second biggest part of the upgrade. The calipers from any 73-78 Ford full-size car will work. The ones I bought were for a 78 Ford Thunderbird. The part numbers are A1 Cardone 18-4083, and 18-4084. They are a bolt-in part with no modification required. They also use the same brake pads as the Bronco. The benefit to these calipers is the larger piston size. The original Bronco caliper's piston measures 2 7/8 inches, and the Thunderbird caliper piston is 3 3/32 inches. That does not seem like a lot but provides much more clamping force.

Comparison pictures of the different calipers

Side by Side ___ Thunderbird Piston ___ Bronco Piston

The only thing left to do is plumb the new calipers. These calipers do not use the banjo bolt like the Bronco's so you will need a few Aeroquip brake fittings, and a stainless braided brake line. The Thunderbird caliper has a 7/16"-24 inlet hole and the Bronco caliper has a 3/8"-24 hole. Aeroquip part #FCM2929 is the fitting adapter you'll need and the aluminum crush washer part #FCM3513. This fitting goes into the caliper where the banjo bolt would go on the bronco caliper. You will need a #3 AN stainless steel flex hose with 90 degree bend on one end and straight on the other. Earl's Performance has a line that is perfect for this application, it is part #630117-14. On the opposite end of the flex hose you'll need Aeroquip part #FCM2936 to adapt it to the 3/16" inverted flare steel line.

Pictures of the fittings and lines

Parts Diagram ___ Crush Washers ___ Bleeder Screws

OK now all we have to do is put it all together.

Install the adapter fitting on the caliper, and don't forget the crush washer.

Install the speed bleeder (Russell part #3959/639590)

Now your ready to put the brake pads on and install the caliper.

You can buy a small parts kit from most parts stores.

Install the anti-rattle clip on the small pad as pictured.

Then install small pad with the anti-rattle clip down.

The large pad goes on as pictured.

Install caliper and tap in the caliper retainer and bolt.

Pic 1 ___ Pic 2 ___ Pic 3 ___ Pic 4

Now remove the brake line support brackets from the axle. The tangs need to be bent open so you can insert the hose to hard line adapter. Then use a vise or c-clamp to bend the tangs back to secure the adapter from coming out.

Pic 1 ___ Pic 2

Attach the braided hose and hard line.

Connect the 90 degree hose end to the caliper fitting.

You will not be able to use the factory stock front brake lines with this conversion unless you cut off the rubber hose section and put a 3/16 nut on and double flare the end. I bought a complete stainless steel hard line kit from Inline Tube. They offer both stainless steel and standard lines that are a perfect fit.

Picture of my lines

Now for the rear brakes you have the option of adding disks with a conversion kit, or keeping the drums but adding F-350 brake cylinders. I chose to keep my drums and add the cylinders because the cost involved in adding disk outweighs the benefit gained. As far as the F-350 wheel cylinders go, just ask your parts guy for 78-79 F-350 4WD rear wheel cylinders. They will bolt on with no mods.

Tighten all your fittings and don't forget to bench bleed your master cylinder before you bleed the brake system.

Right Side Finished ____ Left Side Finished

That's it, you can do the conversion in a day if you have all your parts.

Now go enjoy the ability to actually stop your Bronco!